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Spectroscopy of ultrathin epitaxial rutile TiO[sub 2](110) films grown on W(100)
Epitaxial ultrathin titanium dioxide films of 0.3 to similar to 7 nm thickness on a metal single crystal substrate have been investigated by high resolution vibrational and electron spectroscopies. The data complement previous morphological data provided by scanned probe microscopy and low energy electron diffraction to provide very complete characterization of this system. The thicker films display electronic structure consistent with a stoichiometric TiO2 phase. The thinner films appear nonstoichiometric due to band bending and charge transfer from the metal substrate, while work function measurements also show a marked thickness dependence. The vibrational spectroscopy shows three clear phonon bands at 368, 438, and 829 cm(-1) (at 273 K), which confirms a rutile structure. The phonon band intensity scales linearly with film thickness and shift slightly to lower frequencies with increasing temperature, in accord with results for single crystals. (c) 2007 American Institute of Physics
Modification of the biological intercept model to account for ontogenetic effects in laboratory-reared delta smelt (Hypomesus transpacificus)*
We investigated age, growth, and ontogenetic effects on
the proportionality of otolith size to fish size in laboratory-reared delta smelt (Hypomesus transpacificus)
from the San Francisco Bay estuary. Delta smelt larvae were reared from hatching in laboratory mesocosms for 100 days. Otolith increments from known-age fish were enumerated to
validate that growth increments were deposited daily and to validate the age of fish at first ring formation. Delta smelt were found to lay down daily ring increments; however, the first increment did not form until six days after hatching. The relationship between otolith size and fish size was not biased by age or growth-rate effects but did exhibit an interruption in linear growth owing to an ontogenetic shift at the postflexon stage. To back-calculate the size-at-age of individual fish, we modified the biological intercept (BI) model to account for ontogenetic changes in the otolith-size−fish-size relationship and compared the results to the time-varying
growth model, as well as the modified Fry model. We found the modified BI model estimated more accurately the
size-at-age from hatching to 100 days after hatching. Before back-calculating size-at-age with existing models,
we recommend a critical evaluation of the effects that age, growth, and ontogeny can have on the otolith-size−fish-size relation
Visual Acuity does not Moderate Effect Sizes of Higher-Level Cognitive Tasks.
Background/study contextDeclining visual capacities in older adults have been posited as a driving force behind adult age differences in higher-order cognitive functions (e.g., the "common cause" hypothesis of Lindenberger & Baltes, 1994, Psychology and Aging, 9, 339-355). McGowan, Patterson, and Jordan (2013, Experimental Aging Research, 39, 70-79) also found that a surprisingly large number of published cognitive aging studies failed to include adequate measures of visual acuity. However, a recent meta-analysis of three studies (La Fleur and Salthouse, 2014, Psychonomic Bulletin & Review, 21, 1202-1208) failed to find evidence that visual acuity moderated or mediated age differences in higher-level cognitive processes. In order to provide a more extensive test of whether visual acuity moderates age differences in higher-level cognitive processes, we conducted a more extensive meta-analysis of topic.MethodsUsing results from 456 studies, we calculated effect sizes for the main effect of age across four cognitive domains (attention, executive function, memory, and perception/language) separately for five levels of visual acuity criteria (no criteria, undisclosed criteria, self-reported acuity, 20/80-20/31, and 20/30 or better).ResultsAs expected, age had a significant effect on each cognitive domain. However, these age effects did not further differ as a function of visual acuity criteria.ConclusionThe current meta-analytic, cross-sectional results suggest that visual acuity is not significantly related to age group differences in higher-level cognitive performance-thereby replicating La Fleur and Salthouse (2014). Further efforts are needed to determine whether other measures of visual functioning (e.g., contrast sensitivity, luminance) affect age differences in cognitive functioning
Selection and Development of Replacement Beef Heifers
Selection, development, management, and nutrition of heifer calves to be used as herd replacements are key factors in maintaining beef herd productivity. A cow/calf producer, to be successful, must have some goals or criterion for heifer selection and development. For practically all Utah cattle production areas, economics dictate that heifers must calve as two-year-olds. Heifers must be properly developed and managed to permit this. The following factors are important: Heifers should 1) become pregnant in the first 25 days of the breeding season, 2) give birth to a live calf with little or no calving difficulty, 3) raise a calf to weaning that has an average or above weaning weight, 4) breed back as a two-year-old in the first 45 days of the breeding season, and 5) continue to reproduce and wean a calf each year until 9 or 10 years of age
Morphological and molecular characterisation of a mixed Cryptosporidium muris/Cryptosporidium felis infection in a cat
To date Cryptosporidium muris has been identified by microscopy and genotyping in cats in two studies. We report morphological and genetic evidence of a mixed C. muris and C. felis infection in a cat and provide the first histological, immunohistochemical, in situ hybridisation and genetic confirmation of a C. muris infection in the stomach of a cat. The cat suffered persistent diarrhoea after the initial consultation, which remained unresolved, despite several medical interventions. Further studies are required to determine the range, prevalence and clinical impact of Cryptosporidium species infecting cats
Directions for computational mechanics in automotive crashworthiness
The automotive industry has used computational methods for crashworthiness since the early 1970's. These methods have ranged from simple lumped parameter models to full finite element models. The emergence of the full finite element models in the mid 1980's has significantly altered the research direction. However, there remains a need for both simple, rapid modeling methods and complex detailed methods. Some directions for continuing research are discussed
Gamma ray measurements of the 1991 November 15 solar flare
The 1991 November 15 X1.5 flare was a well observed solar event. Comprehensive data from ground-based observatories and spacecraft provide the basis for a contextual interpretation of gamma-ray spectra from the Compton Gamma Ray Observatory (CGRO). In particular, spectral, spatial, and temporal data at several energies are necessary to understand the particle dynamics and the acceleration mechanism(s) within this flare. X-ray images, radio, Ca XIX data and magnetograms provide morphological information on the acceleration region [4,5], while gamma-ray spectral data provide information on the parent ion spectrum. Furthermore, time profiles in hard X-rays and gamma-rays provide valuable information on temporal characteristics of the energetic particles. We report the results of our analysis of the evolution of this flare as a function of energy (∼25 keV–2.5 MeV) and time. These results, together with other high energy data (e.g. from experiments on Yohkoh, Ulysses, and PVO) may assist in identifying and understanding the acceleration mechanism(s) taking place in this event
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